1. Description of the Prior Art
Kopchik has disclosed in Belgium Pat. No. 848,486 of May 18, 1977 certain novel polyglutarimides prepared by a novel process, having improved properties over any previous polyglutarimides.
Mueller, in Ser. No. 967,663 of Dec. 8, 1978, pending disclosed improving the notched Izod impact strength and Gardner VHIT impact values by blending such polyglutarimides with polycarbonate and multiple stage polymers based on butadiene or acrylates.
While Mueller's invention succeeded in impact modifying the polyglutarimides, the incompatability of polycarbonates with polyglutarimides interferes with the achievement of clear blends. Thus, clear, high impact strength polyglutarimides were not available prior to this invention.
On the other hand, clear, high impact strength vinyl chloride polymers (PVC) were available. They were made by blending any of a wide variety of impact modifiers with the PVC. However it has always been an objective to obtain impact resistant PVC having improved heat distortion temperature. It has been very difficult to achieve significant increases in heat distortion temperature of impact modified vinyl chloride polymers so as to make them competitive with other engineering plastics.
It is an object of the present invention to provide impact resistant polyglutarimides which can be made clear, if desired.
It is a further object of the present invention to provide impact resistant vinyl chloride polymers having improved heat distortion temperatures.
2. Summary of the Invention
These objects, and others as will become apparent from the following disclosure, are achieved by the present invention which comprises blending polyglutarimides and vinyl chloride polymers in a weight ratio of about 5:95 to 95:5.